Machine for separating materials of different specific gravities



Sept. 20, 1955 H. G. CRAM 2,718,179

MACHINE EOE SEPARATING MATERIALS 0E DIFFERENT SPECIFIC GRAvITIEs Filed Deo. 26, 1950 4 Sheets-Sheet l INVENTOR HERVEY @CRAM ATTORNEYS Sept. 20, 1955 H. G. CRAM MACHINE FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GRAVITIES 4 Sheets-Sheet 2 Filed Dec. 26, 1950 INVENTOR u HERVEY G. CRAM W A ATTORNEYS Sept. 20, 1955 H. G. CRAM MACHINE FOR SEPARATING MATERIALS OF' DIFFERENT SPECIFIC GRAvITIEs 4 Sheets-Sheet 3 Filed Dec. 26, 1950 INVENTOR HERVEY G. CRAM ATTORNEYS Sept. 20, 1955 H. G. CRAM MACHINE F'OR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GRAVITIES Filed Dec. 26, 1950 STQCK REGULATOR BOX PULP SCRE N HEAD BOX FOURDRINIER MACHINE 4 Sheets-Shet 4 FAN PUMP INVENTOR HERVEY G.CRAM

ATTORNEYS United States Patent G l 2,718,179 MACHINE FOR SEPARATING MATERIALS OF DIFFERENT SPECIFIC GRAVITIES Hervey G. Cram, Appleton, Wis.' Application December 26, 1950, Serial No. 202,788 6 Claims. (Cl. 92-28) This invention appertains to a novel appliance for effecting the separation of materials of slightly different specific gravities when in liquid suspension, and more particularly to a novel machine for recovering usable materials from a waste liquid.

One of the primary objects of my invention is the provision of a machine operating upon the centrifugal principle of separation, embodying a cylindrical body or casing having rotatable runners therein of' different characters and having an intake head at one end and a discharge head at the opposite end, certain of the runners functioning to confine the material therein and deliver the same to the discharge head, the material of higher specific gravity being (by centrifugal force) positioned at the periphery of the runners, and the material of lower specic gravity at the hub portions of the runners.

Another salient object of the invention, is the provision of novel means for aerating the material as the same enters the intake head, whereby to cause a occulation of usable particles being introduced into the machine.

A further important object of the invention is the provision of a novel runner arranged within the intake head to effect a complete mixture of the liquid suspended material, as the same is introduced into the body.

A still further object of the invention is to provide means for introducing water or other desired liquid between the periphery of certain runners and the inner surface of the body or casing, to effect a steadying reaction on such runners and to establish some buoyancy to the said runners.

While the device is capable of serving to advantage in many types of industry, the principal purpose of the device as illustrated and described in the present case, is in the manufacture of pulp and paper, and a few of these operations within the paper industry to which the device is applicable, are as follows:

(l) The separation of valuable paper-making material from the excess liquid of suspension in the filtrate from the Paper-Machine Wire as effected by the addition of shower water at the screens, head-box etc., so that, the paper-making material may be returned to the fan pump for recirculation of the same to the Paper-Machine Wire, and, provide for the required continuous discharge of the clear liquid of suspension (water) to waste or for re-use.

(2) The separation of the pulp from the liquid of suspension, as in the thickening of the accepted pulp from the screens from a low consistency of around 0.5% to a consistency of 3% or higher, as required for delivery to the beaters or paper-machine, which means, the elimination of Deckers on many grades of pulp, and the assurance of a clear liquid for discharge to waste, or, for re-use.

(3) The separation of objectionable foreign matter from the pulp or paper stock in liquid suspension, such foreign matter, usually being of a higher specific, gravity than the acceptable pulp or paper stock.

With these and other objects in view, the invention consists in the novel construction, arrangement and formation of parts, as will be hereinafter more specifically described and claimed, and illustrated in the accompanying drawings, in which drawings:

Figure l is a longitudinal sectional View through the separating machine, taken on the line 1-1 of Figure 2, looking in the direction of the arrows.

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Figure' 2 is a transverse sectional view through the intake head of the machine, taken on the line 2 2 of Figure l, looking in the direction of the arrows.

Figure 3 is a transverse sectional view, through the machine taken on the line 3--3 of Figure l, looking in the direction of the arrows and illustrating one of the enclosed runners.

Figure 4 is a transverse sectional View through the4 machine, taken on the line 4 4 of Figure l, looking in the direction of the arrows and illustrating the inner and outer discharge openings of the outermost enclosed runner.

Figure 5 is a transverse sectional view through the discharge head of the machine, taken on the line 5--5 of Figure 1, looking in the direction of the arrows.

Figure 6 is an enlarged fragmentary detail verticaly Vin any preferred way, such as by bolts 14. Secured to the opposite terminals of the body 10, is an intake head 15 and a discharge head 16. These heads 15 and 16 terminate in bearing casings 17 and 18, respectively, and these bearing casings support bearings 17 for a main shaft 19, which extends axially through the body 10 andv the heads 15 and 16. This shaft 19 can be directly driven from a suitable motor, not shown. The lower section 12 of the body 10 can have cast thereon any preferred type of base 20, whereby the separating machine can be rigidly secured to a floor, or other desired base. However, it is to be understood that the separating machine S can function either in a horizontal plane, as shown, or in a vertical plane.

Communicating with the intake head 15, is a pipe 21 for the delivery of material (in liquid suspension) into the intake head and the body 10. The rate of volume flow through the pipe 21 is controlled by a valve 22. By referring to Figure l, it can be seen that the pipe 21, at its point of connection with the intake head 15, is slightly restricted, as at 23, and that the pipe gradually tapers toi ward said restricted portion. Positioned in the pipe 2l, directly above the restricted portion 23 of the pipe, is an aerating jet 24, for a purpose which will be later set forth. It is to be noted that air under pressure is fed to the jet 24 by means of a tube 25, which extends into the pipe 21 through a packing gland 26, and the rate of ilow of compressed air through the tube 25 is controlled by a hand operated valve 27.

The aerating jet 24 consists of a lower housing shell 28, having tted therein a closure cap 29. The cap is provided with a central hub portion 30, and the shell 28 and the cap 29 are connected by means of a machine screw 31, which extends through the shell 28 axially into the hub 30. The upper portion of the hub 30 is provided with an axially disposed opening 32, with which the tube 25 communicates, and the hub is provided with outlet orifices 33, which connect the opening 32 with the interior of the shell. The side wall 34 of the cap is provided with orices 35, which communicate with an annular cavity 36 formed in the inner face of the shell and this cavity opens out through the upper face, at the rim, of the jet. At this time, it can be seen that, as material flows through the pipe 21 toward the head 15 that compressed air meets the material so as to effectively aerate the same. The purpose of this aerating action will be later brought out, as stated above.

Keyed or otherwise rigidly fastened to the shaft 19, is a' series of abutting runners 37,; 38, 39 and 4t). The runner 37 is disposed directly within the intake head 15, and isy of a diierent character than the runners 38, 39 and 4t), which are arranged within the body 10. The function of the runner 37 is also different than the runners' 38, 39 and 40.

The runner 3,7, includes a hub 41, and radially extending apertured blades 42, which function in the nature of beaters, and the runner 37 etects a vcomplete mixture of the liquid suspended material, as delivered through pipe 21. The runner 37 also functions to effect a partialrotation of the material at the lateral entry into the range of the'runn'er 38. y

The runners 38, 39 and 4t), are ofsimilar construction and have similar functions. The runner 33, includes a hub 43 and radially extending imperforate blades 44. The blades 44 are connected by acircular rim 45. The runner 38, Val'solin'cludes Yan outer, disc shaped -wall 46, Vwhichis connected to theblades 44'. The Wall 46 adjacent to theV hub 43, is provided with an annular opening 47, through which the aerated. and mixed material iiows into the runners, 38, 39 and 40. The runner 39, includes a hub 43, carrying a plurality of radially extending blades 49, and the outer ends of the blades 49 are connected by a cylindrical rirn 50. It is to be noted that this runner 39 has both ends open for the free how of material therethrough. The runner 40 includes aA hub 51 and a plurality of radially extending blades 52, the outer ends of which are connected by a cylindrical rim 53. This runner 40', is also provided with an outer disc shaped end wall 54 which is rigidly connected with the sides of the blades 52. This end wall 54 is provided with a peripheral circular opening 55, and an inner circular axial opening 56. The opening 55 is provided for the discharge of material of higher specic gravity and the circular opening 56 for the discharge of materialof lower specific gravity. At this time, it is to be noted that the lirns 45, 50 and 53 Of the runners 38, 39 and 40, are slightly spaced from the inner surface of the body 10` and function to conne the material within the runners. y y As the shaft I19 is drivenat a relativelyhighvrate of speed, I preferably introduce water, or other desired liquid, between they inner surface of the body 10 and the rims oftherunners. This canbe accomplished through the medium of a water delivery pipe 57, which communicates with the interior o f the body. Flow of water through the pipe '7 is controlled by a hand valveSS. A required pressure on the water may be retained between the body and the rims of the runners 38, 39 and 40, to establish somebuoyancy f or the cylindrically enclosed runners, and to effecta steadyingreaction thereon. y Y Y Atten'fon is now directed to the discharge head 16and the same formed with a cylindrical outer chamber 59 for the reception ot' the heavier material discharged through the peripheral opening 55 and an inner chamber A60 for the reception of `the lighter aerated material y'discharged through lthe axial opening 56. The heayier material 'from chamber 59 flows into a pipe 61, which leads to a waste sewer or other desired point, as will be later brought out. The rate of volume flow of the heavier material through pipe 61,.is controlled by a valve 462. The lighter lmaterial in chamber 6() is discharged into a pipe 63and the rate of volume ilow through this pipe is controlled byl a valve64, and this pipe, can lead to a desired delivery point, Vas will also be later brought out. A

Figure 7, of the drawings, one use ofthe improved separating device S is shown, and the sameis used to receive ywater drained from the paper Vstock tlowing over a wire 65, of af Fourdrini'er machine 66. Pulp, or paper stock, is supplied to the wire by means of a head box 67, whiehin turn is supplied., from a pulp screen 6.8,. Asis ordinary practice, the 'pulp 'or stock is initilly 'received within a stock regulator box 69,- and is pumped to the.

screen by a pump 70. A pipe 71 connects the head box with the pump and the pump `is in turn connected to the screen by a pipe 72. The water draining from the wire is caught in a pan 73y and leading from the pau is' a drain pipe 74, which can be connected to the head box pipe 71. This pipe 74 is connected to the intake pipe 21 of the machine by a length of pipe 75. The flou/.0f material from the pipe 74 tothe separating machine S is governed by a liquid level controller 76.

In operation of the separating machine S, the dilute mixture of pulp or paper stock, and water, isl introduced into the machine from the pan 73 to the pipe 21, wherein the mixture is thoroughly aerated by the aerating jet 24.

The dilute mixture is rst introduced into the machine' a't the intake head 15, and then into contact with the mixing' runner 37. This runner thoroughly agitates the mixture and transmits a rotation thereto previous to the lateral entry of the mixture at or near theaxis to and through the cylindrically enclosed runners 38, 39 and 40. The cylindrical rims of these runners confine the mixture and at the same time, the rapid rotation thereof (through centrifugal force) moves the material of higher specific gravity toward the cylindrical rims. The material of lower specic gravity, i. e., aerated pulp, or paper stock, is discharged at the axial opening 56 to the chamber 60 and to and through pipe 63, as controlled by the valve 64, and this material is returned to the head box or to the pump 70. The heavier liquid, i. e., water plus particles o'f foreign matter may not have been effected by aeration or, which may be of a higher specific gravity than the pulp or paper stock, is conned in the periphery of the cylindrical enclosure of the runners 38, 39 and 40,v as stated, by centrifugal force, and ejected through the peripheralV opening 55 to chamber 59 and discharged therefrom through the pipe 61 with the rate of ow controlled by the valve 62.

It will be apparent that the rate of ow through the pipes 61 and 63, as controlled by the position of the valves 62 and 64, will determine the consistency of the segregated pulp or paper stock.

Inthe separtionof pulp or paper stockl from its liquid of suspension (water), that water will not be aerated by ordinaryv means, such as is provided by this device. This is of advantage, in that, it is essential that the specitic gravity of the liquid should not be reduced.

Aeration, as herein referred to, means air adherence i to, or air ahsorbence by, a particle of material, such as lill pulp or paper stock, with the result that its specilic gravity is reduced, thus bringing about some differentiation between the material and the liquid suspension.

It should be noted, that aerated pulp or paper stock become unaerated, partially or as a whole, if alloived to stand for any length of time in a settling tank, or the like, and, it will be apparent that any pulp or pa# per-stock which does become unaerated under this con-` dition lwould result in the pollution of the water of dilution as separated ott by means of settling tanks, etc.

In connection with the above, it is well to note, that with the machine S, the total elapsed time from the point of aeration through the field of centrifugal separation to segregation of the pulp or paper-making material and the liquid of dilution, is less than live seconds. y r

Referring to the separation of objectionable foreign matter from the pulp or paper stock in liquid suspension,y

it will be observed that as the thickened pulp is discharged from the ,axis of the body that foreign matter or dirt will be extracted from the pulp and discharged with the liquid of suspension with great eiciency.

Theory That the time of separation of ra maten 1 of a1wt specific gravity from its liquid of suspension in a still pool such as a tank is not affected by the depth, in that, while the rate of settling, in the case of material heavier than the liquid of suspensio i, or the rate at which material lighter than the liquid of suspension will rise increases with the hydrostatic pressure which is relative to the depth of the pool; however, this is off-set by the relatively increased distance which the material must travel to the top, or bottom of the pool as the case may be.

The design of the separating machine S as shown in Figure 1 of the drawings, and with the shaft and runners rotating at 1200 R. P. M., provides for a pressure range of zero at the axis to 94 feet (static pressure head) at the confining cylindrical (peripheral) section of the runners, and at the same time, the distance of travel of the material for separation is restricted to 61A or .553 feet.

Based on the above, the rate of travel of separation in the separating machine S would be equivalent to that within a still pool having a depth of 94 feet; however, the distance of travel separation in the machine S being actually 0.553 feet, the rate of separation in the machine would have to be:

l O S, or 170 times that of tank (still 13001) Separation and, based on a lateral ow through the machine of 900 G. P. M. the actual time of positive rotation would be:

pool) was accomplished in three minutes, or, 180 seconds, therefore,

180 Sec. 0.553 feet (Depth of Pool) 0.825 Sec. (per ft. of cylinder) 94E ft.

(Equivalent head in machine) 1.28 feet is the length of cylinder required for this particular material in liquid suspension for machine S separation, based on passage through at the rate of 900 G. P. M. The purpose of the above is to indicate the basis for design, in that, with a sample of a proposed material to be treated at hand, a simple laboratory test can be made, which, plus the capacity required, is not only the information for design, but it also predetermines the success to be expected from the machine S operation on any liquid suspended material.

It is Well to note that some materials are suiciently heavy, with relation to the liquid of suspension as to permit separation without aeration, in fact, may not be aiected by aeration, in which case, separation is reversed in the machine S, in that, the material will be discharged through the peripheral slot (55) and the liquid of suspension through the axial opening (56).

It is well to note that there are some materials which present very stable liquid suspension, and which cannot be aerated. These materials are not subject to separation either by the machine or still pool settling, however, most pulp and paper stocks and all white water are Within the range of machine separation.

Changes in details may be made without departing from the spirit or the scope of this invention, but what I claim as new is:

1. A device for continuously separating materials of different specific gravities in liquid suspension comprising a cylindrical body, an intake head at one end of the body communicating therewith, a discharge head at the opposite end of said body, said discharge head having an inner chamber and an outer chamber, a pipe for continuously supplying liquid carrying solids to the intake head, end and intermediate rotatable runners in the body extending substantially the full length thereof for rapidly rotating the liquid in the body, all of said runners including axial hubs, cylindrical rims and blades connecting the hubs and rims, the end runners having outer walls facing the intake and discharge heads, the outer wall of one end runner having an axial opening communicating with the inlet head, the outer Wall of the other end runner having an axial opening communicating with the inner chamber of the discharge head, and a peripheral opening communicating with the outer chamber of the discharge head.

2. A device for continuously separating materials of diiferent specilic gravities in liquid suspension as defined in claim 1, and an aerating jet in said supply pipe disposed adjacent to the inlet head.

3. A device for continuously separating materials of different specific gravities in liquid suspension as deined in claim 1, an aerating jet in said supply pipe disposed adjacent to the inlet head, and a rotatable agitating and mixing runner in the intake head.

4. A device for separating continuously materials of diierent specific gravities in liquid suspension, comprising a cylindrical body, an intake head at one end of the body communicating therewith, a discharge head at the opposite end of the body, said discharge head having an inner chamber and an outer chamber, means for continuously supplying liquid containing solids to the intake head, and rotatable runners in the body extending substantially the full length thereof for rapidly rotating the liquid in the body, said runners having rotatable rims for conning material at the periphery of the runners, said body and discharge head having communication adjacent to their axis for delivery of material of light specific gravity from the runners to the inner chamber, and said body and discharge head having communication adjacent to their peripheries for discharge of material of higher specic gravity from the runners to the outer chamber, an aerating head disposed in the means for continuously supplying liquid containing solids to the intake head, and means for supplying compressed air to the aerating jet, said aerating jet including a shell, a cap closing the shell having an axial hub, said hub being provided with an axial chamber for receiving compressed air from said supply means, said hub having ports connecting the chamber with the interior of the shell, and said shell having a peripheral outlet cavity at its upper end communicating with the interior of the shell.

5. A device for continuously separating materials of diierent specilic gravities in liquid suspension as defined in claim 4, and a mixing runner rotatably mounted in the intake head including perforated blades.

6. A device for continuously separating materials of dilerent specic gravities in liquid suspension as defined in claim 4, an aerating head disposed in the means for continuously supplying liquid containing solids to the intake head, and means for supplying compressed air to the aerating jet, and a rotatable agitating and mixing runner in said intake head having perforated blades.

References Cited in the le of this patent UNITED STATES PATENTS 864,856 Norris Sept. 3, 1907 1,576,108 Fogler Mar. 9, 1926 1,701,942 Andrews Feb. 12, 1929 1,747,155 Birdsall Feb. 18, 1930 1,770,430 Respress July 15, 1930 2,033,123 Cowles Mar. 10, 1936 2,209,339 Knight July 30, 1940 2,220,574 Little et al. Nov. 5, 1940 2,323,056 Labour June 29, 1943 2,336,150 Horvath Dec. 7, 1943 2,510,781 Howard lune 6, 1950 FOREIGN PATENTS 306,954 Germany July 26, 1918 889,192 France Jan. 3, 1944 

